Variable load brake



S. L. WILLIAMS VARIABLE LOAD BRAKE Feb. 23, 1937.

Original Filed Aug. 5l, 1934 3 Sheets-Sheet 1 Feb. 23, 1937.

S. L, WILLIAMS VARIABLE LOAD BRAKE 3 Shets-Sheet 2 Original Filed Aug. 31, 1934 NWN @W Q t t SAMUEL I .WILLIAMS ATTORN EY Feb. 23, 1937.

S. L. WILLIAMS VARIBLE LOAD BRAKE Original Filed Aug. 51, 1934 3 Sheets-Sheet 3 Y C \t/m E m0 mm z F @e XE m DVU w Mm @n Ww EP E N O Z 2 M ,M06 m r o HELE/4 PO S/ 7'/O/V PO /T/ON Y 5 CN N. E/ RH Y MT mw m 5 EQ/v NL WR E o MO E VL f n i EP N mw w A n Tl MW F- A C O/ E SVI 6 3 B 96u: m 6 a 8 E 32 E E 7 9 8 6 6 6 2 7 E 5 a 6 E 6. Mm 3 8.,r EN Y .3 /60 3 MW MN @Q 4 867@ E@ fw .MMOG 55 6 67 5 L GT 8 65 Eo R/ e RP Ww u M P s@ 6 4 3 e E C 5 f 7 N M 6 6 z a M5, mw M fw ww E e 6 m E/ m o R O 6 3 9 2. a @me f6 e 6 www wow .www s e 8 EN 3 6 5m V e Q Q MW 5 25 5 mm e6 a@ f n Patented Feb. 223, 1937 VARIABLE LOAD BRAKE Samuel L. Williams, New York, N. Y., assigner to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Original application August 31, 1934, Serial No.

Divided and this application November 19, 1935, Serial No. 50,525

1s claims. (Cl. 30s- 22) j y This invention relates to kbrake systems for trains and more 'particularlyl to a brake system of the electropneumatic type, and is a division of my copending application, Serial No. 742,261, filed August 31, 1934.

One object of the invention is to provide improved means or regulating the degree of an application of brakes on a car according to the load on the car. v

Another object of the invention is to provide in connection with a brake control system( of the type embodying rboth pneumatic and electropneumatic brake control means, improved means for regulating, according to the load on a car, the degree of application of brakes effected upon operation of-either of said control means.

Other objects and advantages will be apparent from the following more detailed description of the invention.

Inthe accompanying drawings; Figs. 1-1A are diagrammatic views, mainly in section, of an electropneumatic brake equipment embodying the'invention and showing the apparatus adapted to be employed on the leading or control car of a train, said apparatus including that adapted to be employed on cars of the train other than the leading car, Fig. 1A being a continuation of Fig. 1; Figs. 2, 3, 4, Vand 5 are sectional views taken on the line 2 2, 3 3, 4-4 and 5 5, respectively, through the brake valve device shown in Fig. 1; Fig. 6 is an enlarged view of a switch shown in Fig. l associated with the brake valve device; Fig. 7 is a View similar to Fig. 6 but showing the switch in a diiierent operating position; and Fig. 8 is another View of the switch shown in Figs. 6 and 7.

, As shown in the drawings, the brake equipment adapted to be carried only on the control car of a train comprises a combined brake valve and brake switch device I and an electropneumatic control device 2, While the apparatus adapted to be employed on the control car as well as all other cars of the train comprises a pneumatic brake controlling Valve device 3 for controlling the brakes on a car pneumatically, an electric brake controlling valve device 4 for controlling the brakes on a car electrically, a relay valve rdevice 5 adapted to be controlled by the electric brake controlling valve device 4, a variable load mechanism 6 for controlling the degree of brake application effected by said electric brake controlling valve device 4 and pneumatic brake controlling valve device 3, and a double check valve device 1. The control car apparatus may further comprise amain reservoir 8 which is connected to a main reservoir pipe 9v adapted to extend through the train, a feed valverdevice IIJ, and a source of electrical energy such as battery II, while each car of the train is provided with the usual auxiliary reservoir I2 associated with the pneumatic brake controlling valve device 3, and the usual brake cylinders I3.

The brake valve portion of the combined brake valve device and brake switch device I is of the type known as the self-lapping type and comprises a ,casing having a chamber I4 connected at all times to a brake pipe I5 which extends through the train, and further comprises a brake pipe charging valve I6 for supplying fluid under pressure to chamber Ill and from thence to brake pipe I5and a brake pipe discharge valve Il for venting uid under pressure from said chamber and brake pipe. The supply valve I6 is contained in a chamber I6, which is connected to a passage i9 leading to the feed valve device I@ and is subject to the pressure of a spring 2U adapted to urge said valve to its seat. y The discharge valve I1 is carriedv by a movable abutment 2l, and a spring 22 contained in said abutment is provided to urge said valve from its seat. The movable abutment 2I is subjecton one face to the pressure of fluid in chamber M and on the opposite face to the pressure of an yadjustable control spring 23 which is contained in a chamber 24, said chamber being at all times opento the atmosphere through an atmospheric vent passage 25.

A ulcrum member 26 is slidably mounted in a suitable bore in the casing of the brake valve device and a beam. 2l is pivotally mounted, intermediate its ends, on a pin 28 carried by the fulcrum member 26. One end of beam 2l carries a push rod 29 the free end of which engages the supply valve I6 in a recess 3U, while the other end of said beam carries a roller 3| which engages the stem 32 of the brake pipe discharge valve I'I. .1 'y

A rotatable stern 33 is suitably journalled in the brake valve casing and extends through chamber I4 and chambers 34 and 35 formed in said casing, and a collar A3b is provided on said stem within chamber I4 between which and the casing surrounding said stem isprovided a gasket 31 to prevent leakage from. chamber i4. A brake valve handle 38 is secured to said stem, outside of the casing, for turning said stem. The brake valve casing is provided with a quadrant 50, and the handle 38 `is provided with a spring pressed latch 5I adapted to slide over said quadrant and drop into a notch 52 for dening the termination of a certain brake control Zone, while the quadrant is provided at opposite ends with outstanding lugs 53 and 54 adapted to be engaged by said handle for defining the extreme positions of said handle, the various controlling positions of said handle being indicated in Fig. 2.

A cam 39 is provided on the stem 33 in chamber i4 in operating alignment with the fulcrum member 26 and is adapted upon turning said Stem by handle 38 from release position through the service Zone to vary the position of the ulcrum member 26, as will be evident from an inspection of Fig. 5, for controlling the operation of the charging valve I5 and discharge valve I1.

A brake pipe vent valve 40 is contained in a chamber 4| which is connected to a passage 42 leading to the brake pipe chamber I4, and a spring 43 also contained in chamber 4| acts on said vent valve to urge same into engagement with seat rib 44. The chamber 4| is open through an aperture 45 to a chamber 4S which in turn is open to the atmosphere through an atmospheric vent passage 41. A stem 48 carried by the vent valve 49 projects through aperture 45 and a suitable bore in the casing wall separating chambers 35 and 46, and into chamber 35, and a cam 49 carried by the stem 33 in chamber 35 is provided to unseat the vent valve 40 when the brake valve handle 38 is moved to emergency position, as will be noted from an inspection of Fig. 3 of the drawings.

The combined brake valve device and brake switch device is provided with an outstanding lug 55 having oppositely disposed ears 58 and 51 carrying two toggle switches. One of the toggle switches comprises a switch arm 58 one end of which is pivotally mounted on a pin 59 in the ear 55,'while the other end of said arm is provided with a contact 6D which is insulated from said arm and adapted to engage a fixed contact GI. One end of a spring 62 is connected to a pin 53 provided in the outer end of arm 58 while the other end of said, spring is connected to a pin 64 in the lug 55, said spring being provided to snap the contact 60 to a circuit opening and a circuit closing position after the arm 58 is moved, by means to be hereinafter described, to a position in which the force of said spring acts at either one side or the other of fulcrum pin 59. The other toggle switch comprises a switch arm 55 one end of which is pivotally mounted on a pin 69 in the ear 51, while the other end is provided with a contact 61 insulated from said arm and adapted to engage a fixed contact 98. One end of a spring 69 is connected to a pin 18 provided in the outer end of arm B5 while the other end or" said spring is connected to pin 84 in the lug, said spring being provided to snap the contact 81 to a circuit opening and circuit closing position as above described in connection with spring 62.

A lever 1| is provided to control the operation of the toggle switcharms 58 and 65. The lever 1| is pivotally mounted intermediate its ends on a pin 12 provided in the end of a fulcrum rod 13 which is supported by the casing of the combined brake valve and brake switch device I, and slidably extends through a suitable bore in said casing into a chamber 15. A roller 16 is provided in the end of the fulcrum rod 13 in chamber 15 and engages a cam 11 on the rotatable stem 33, and a spring 18 surrounding rod 13 within the chamber 15 acts on a collar 19 on said rod urging the roller 16 against the cam 11.

The toggle switch arms 58 and B5 are operatively connected to the lever 1| at one side of the fulcrum pin 12 by means of rods 8|) and 8|, respectively, which are pivotally connected tc the respective switch arms and freely extend through openings in the lever 1|. The rod 89 is provided on its free end with a button 82 adapted to be engaged by one side of lever 1|, while spaced from said button and on the cpposite side of the lever 1| a collar 83 is provided adapted to be engaged by said opposite side of said lever, the difference between the space between adjacent faces of the button 82 and col lar 83, and the thickness of the lever between said adjacent faces being provided to permit the snap movement of switch arm 58 due to the action of spring 62, as will be hereinafter described. The rod 8| is provided with a button 84 at its free end and a collar 85 lspaced from sai-: button and on the other side of the lever arm 1I to provide for snap operation of switch arm 65 by spring 69. Stop lugs 321 and 328 are provided on ears 56 and. 51 to be engaged by switch arms 53 and 55, respectively, to dene the circuit open position of said arms.

A piston 86 is contained in the casing of the combined brake valve and brake switch device and is provided with a stern 81 which freely extends through a suitable bore in the casing and is pivotally connected by a pin 88 to the end of lever 1I opposite the end for controlling the toggle switches. The piston 83 has at one side a control chamber 89 connected to a passage 98 leading to a timing reservoir 9|, and has at the `opposite side a chamber 92 open at all times to the atmosphere by way of clearance space between the stem 81 and the casing, A spring 93 contained in chamber 92 is provided to urge the piston 83 towards the left hand.

The electropneumatic control device' 2 is provided to supply fluid under pressure to and release fluid under pressure from the timing reservoir 9| and comprises an application control valve 94, a release control `valve 95, an application magnet valve device for controlling the valve 94 and a release magnet valve device for controlling the valve 95. The application control valve 94 is in the form of a valve piston having at one side a chamber 98 which contains a spring 99 for urging said valve into engagement with a seat rib |09 formed in the casing. The release control valve 95 is also in the form of a valve piston having at one side a chamber |9| which contains a spring |02 for urging said valve into engagement with a seat rib |83 formed in the casing. The application magnet valve device comprises an application control magnet 96, a double beat valve |84 contained in a chamber |95 and having a fluted stem |05 extending through a bore in the casing into a chamber |81 which is vented to the atmosphere through an atmospheric passage |88, and having another fluted stem |89 extending through a bore in the casing into a chamber II). A spring is contained in the chamber H9 and acts on a plunger ||2 urging said plunger against the end of the uted stem |89. The release magnet valve device comprises a release control magnet 91, a valve I3 contained in a chamber I4 which is vented to the atmosphere through an atmosa pheric vent passage 5, and a valve ||6 contained in chamber I1, both of said valves having a uted stem extending through suitable bores in the casing and engaging in a chamber I8. A spring ||9 is disposed in chamber ||1, and acts on the valve I6 to urge said valve to its seat and at the same time urge valve 3 away from its seat.

The pneumatic brake controlling valve device 3 comprises a service valve device |28, an emergency valve device |2l, a brake pipe vent valve device |22 and a high pressure valve device |23.

The service valve device |28 comprises a piston |28 having at one side a chamber |25 connected through chamber |37 and passage |38 to a passage |28 leading to brake pipe i5 and having at the opposite side a valve chamber |21 connected to a passage |28 which in turn is connected to a pipe |29 leading to auxiliary reservoir i2, said service valve device further comprising a main slide valve |38 and an auxiliary slide valve |3| contained in chamber |21 and adapted to be operated by piston |28. A spring pressed stop |32 projects into piston chamber |25 and is adapted to be engaged by the piston |28,

The emergency valve device |2| comprises a piston |34 having at one side a chamber |35 connected to a passage |36 leading to `chamber |31 in the service valve device, which chamber is connected through a passage |38 to passage |26 leading to brake pipe l5. The piston |38 has at the opposite side a chamber |38 connected to a passage |88 leading to a quick action chamber |4| and containing a main slide valve |42 and an auxiliary slide valve |83 adapted to be operated by piston |34. For operating the slide valves |82 and |43, the piston |38 is provided with a stem |48 extending into chamber |39, said stem having a recess for receiving the auxiliary slide valve |83 and spaced shoulders |85 and |88 adapted to engage the main slide valve |82 for operating same. The stem |88 is provided with a recess which cooperates with a recess in the top of the auxiliary slide valve |83 to form a pocket Ml which contains a charging check valve |48 adapted to seat v on said auxiliary slide valve. A movable spring pressed stop member |88 projects vinto piston chamber |35 and is adapted to be engaged by piston |38.

The brake pipe vent valve device |22 comprises a vent valve |58 contained in a chamber |5| which is connected to passage |26 leading to brake pipe |25. Asp-ring |52 is contained in chamber |5| and acts to seat said vent valve, and a piston |53 is provided for unseating said vent valve, said piston having at one side a chamber |511 connected to a passage |55 leading to the emergencyvalve device |2l, and having at the opposite side a chamber '|88 which is open to the atmosphere at all times through a port itil, chamber |58 and passageway |59.

The high pressure valve device |23 comprises a valve |68 contained in a chamber |8| which is connected by a passage |82 to the main reservoir pipe 9, a spring |83 contained in said chamber for seating the valve |88, a plunger |88 for unseating said valve, and a piston |85 for actuating said plunger, said piston having at oneA side a chamber |88 connected to passage |55, and at the opposite side a chamber |82 which is connected to the atmosphere at all times by way of passageway |68. The valve |68 has a fluted stem |89 which slidably extends into a suitable bore in the casing into engagement with plunger |84, while the plunger is provided with a valve |78 around its cuter end, and a plurality of peripheral grooves lll below the valve, to prevent leakage past said plunger when the valve |88 is unseated.

rlFhe electric brake controlling valve device 4 comprises a release magnet |l2, a release valve |13 adapted to b'e seated upon 'energization of said magnet and contained in a chamber |14 which is open to the atmosphere through a passage ll. A uted stem |18 projects from said valve through a suitable bore in the casing into a chamber Ill, and a spring |78 contained in said chamber acts `ona plunger W9 to urge said valve from its seat. The electric brake controlling valve device further comprises an application magnet |88, a valve |8| contained in a chamber |82 and a valve |83 contained in a chamber |84. Each valve |8| and |83 is provided with a iluted stem which engage one another in a chamber |85, and a spring |89 contained in chamber |89 acts on valve |83 urging valve |83 to its seat and valve |8| away from its seat.

The relay valve device 5 comprises a piston |81 having at one side a control chamber |88 and at the opposite side a chamber |89. A stem |98 projects from said piston into a valve chamber 19|, and a baiile piston |92 is provided on said stem separating chambers |89 and |9|. A brake cylinder release valve |93 is disposed in the valve chamber |9| between spaced shoulders |88 and |95 on the piston stem |98 and is adapted to be operated by the piston ll. An application valve |88 is disposed in a chamber |82 Vfor controlling communication fro-m a fluid pressure supply chamber |98 to valve chamber i9 l, and an application valve pilot valve |99 is mounted within the application Valve |93 for co-ntrolling communication from chamber 9| to chamber |8|, the appli-v cation valve |98 and pilot valve V|98 being arranged in axial alignment with the end of piston stem |98 and adapted to be successively unseated by said stem. A spring 288 is provided in chamber |87 and acts on the application valve |88 urging same into engagement with a seat rib 28| while a spring 282, within spring 288, acts on pilot valve |98 urging said pilot valve into engagement with a seat rib 283 provided in the application valve |98. A passage containing a restriction 288 provides la communication from chamber1 |88 to chamber |92.

The variable load mechanism 8 comprises a brake cylinder pressure limiting valve device 285, adjusting mechanism 288, and a oy-pass valve device 281.

The limiting valve device 285 comprises a casing having a chamber 288 containing a valve 288 which is provided with a iluted stern extending through a suitable bore in said casing and into a chamber 2|!) at one side of a flexible diaphragm 2|| which engages said stem. A spring 2|2 in chamber 288 acts on the `valve 288 urging same to its seat, while a spring 2 i3 acts on the diaphragm 2|I for urging the Valve 288 away from its seat. A movable plunger 2|@ is slidably mounted in a suitable bore in the casing and engages one end of spring 2|3, and an adjusting screw i is carried by said plunger and is adapted to be engaged by an arm 2|8 secured to a shait 2|'| which is rotatably carried in a bracket 2 i8 formed integral with the casing.

Also secured to the shaft 25| is an arm 2|9, which, at its free end, is provided with a curved surface 228 in the form of an arc of a circle.

The adjusting mechanism 288 comprises a casing containing a strut piston 22| having a stem 222 which extends through an opening in the casing and which, adjacent its outer end, is operatively connected to a lever 223 by a pin 228. The piston 22| has a chamber 225 at one side which is constantly connected to a pipe 228 through which fluid under pressure is adapted to be supplied for eiecting the operation of a door engine 221 to open the door of a'car. AAt the opposite side of piston 22| is a chamber 228 ontaining a spring 223 provided to urge the piston 22| to the normal position, as shown in the drawings.

An arm 233 is also secured to the shaft 2 I1, the free end of said arm being connected to one end of the lever 223 by a link 23 while the other end of the lever 223 is connected to one end of a tie rod 232 the other end of which connects to one arm of a bell crank lever 233 which is pivotally mounted on the body of the vehicle. The other arm of the bell crank lever 233 is provided with a roller 234 adapted upon clockwise rotation of said lever to engage a portion, such as the spring plank 235, of a car truck.

The casing further contains a locking piston 236 having at one side a chamber 231 connected to a passage 236 leading to the strut piston chamber 225, a spring 233 being provided to act on the other side of said piston to urge same to the locking position, as shown in the drawings.

The piston 236 is provided with a stem 246 which is connected to one end of a lever 24| which is fulcrumed intermediate its ends on a pin 242 carried by the b-racket 218. A link 243 is connected to the other end of lever 24| and a friction locking element such as roller 244 is carried by said link and disposed between the curved surface 226 of arm 2|9 and a surface 245 of a lug 246 carried by the bracket 2|8, surface 245 being so arranged with respect to the curved surface 226 that the roller 244, upon downward movement, acts as a wedge to lock the arm 219 in an adjusted position The by-pass valve device 201 comprises a movable abutment 241 having a chamber 248 at one side connected to a passage 246 leading to diaphragm chamber 2 Il), and having a chamber 250 at the opposite side containing an adjustable spring 25| which acts on said abutment to urge same to the normal position, as shown in the drawings. The abutment 241 is provided with a pin 252 which extends through an aperture in the casing into a chamber 253 wherein, said pin normally engages and holds unseated a valve 254 which is subject to the opposing pressure of a spring 255 acting to seat said valve.

Also secured to the shaft 2|1 are arms 256 and 251, the arm 256 being movable along a contact plate 25S for varying the resistance in a power circuit of the control car according to the load carried by said car, while the arm 251 is connected by a link 259 to the stem 260 of a volume varying piston 26| which is provided at one side with chamber 262 the volume of which is adapted to be varied according to the load condition of the car.

A double beat valve 253 is contained in a chamber 264 which is connected to a passage 265 leading to chamber 262 and is adapted to control communication between chamber 264 and chambers 266 and 261. A stem 268 connects the double beat valve 263 to a piston 263 having at one, side a chamber 212 which is connected to the door opening pipe 226, and having at the opposite side a chamber containing a spring 21| acting on said piston urging same to the normal position, as shown in the drawings. Y

The adjustment of the variable load mechanism according to the load on a car is accomplished in the following manner.

When fluid under pressure is supplied to pipe 226 to effect the operation of door engine 221 to open the door of the car, in the usual well known manner, uid under pressure also flows from said pipe to the strut piston chamber 225 and from thence through passage 238 to the locking piston chamber 231, and also from pipe 226 to piston chamber 21|). Fluid under pressure thus applied to the strut piston 22| moves said piston outwardly against spring 229 into engagement with a shoulder 212 in the casing, and thereby rotates lever 223 about its fulcrum connection with link 23| until the roller 234 engages the spring plank 235 on the truck. When sufcient pressure has been built up in chamber 231 on the locking piston 236 to overcome spring 239, said piston is moved downwardly which actuates lever 24| to move roller 244 out of locking engagement with surfaces 226 and 245, and at substantially the same time, the piston 269 is moved against spring 21| and seats the double beat valve 263 in its left hand position in which the volume piston chamber 262 is opened to the atmosphere through passage 265, chamber 264 and atmospheric chamber 261.

With the variable load mechanism in the condition just described, the limiting valve spring 2|3 acts thrcughplunger 2|4, screw 2|5, arms 2|6 and 232, link 23|, lever223, tie rod 232 and the bell crank lever arms to hold the roller 234 against the car spring plank 235. Now if the load on the car is increased, the body of the car sinks toward the spring plank 235 and thereby operates the bell crank lever arm 233 to turn the shaft 2|1 in a clockwise direction, thereby operating the arm 296 to move the plunger 2| 4 inwardly and compress or increase the pressure of the limiting valve spring 2|3. This rotation of shaft 2|? also acts through arm 251, link 25S and stem 266 to move the piston 26| upwardly and thereby decrease the volume of chamber 262. In case there is a reduction in the load carried by the car and the car body moves away from the spring plank 235, the limiting valve spring 2|3 expands in order to maintain roller 234 in engagement with spring plank 235 and in so doing the pressure of said spring is reduced and the consequent rotation of shaft 2i 1 in a counterclockwise direction pulls the piston 26| downwardly thereby increasing the volume of chamber 262. In other words the pressure of the limiting valve sp-ring 2|3 is increased upon an increase in car load and reduced upon a reduction in car load, while the volume of chamber 262 is reduced upon an increase in car load and increased upon a reduction in car load, and it will be further noted that, since the arm 2|9 is secured to shaft 2|1, its position also changes according to the car load.

When the car has been loaded, the pipe 226 is vented'to the atmosphere to permit the door engine 221 to operate to close the door of the car.

With the pipe 226 thus vented to the atmosphere, the piston chambers 231, 225 and 210 are consequently vente-d. It will here be noted that the pressure of spring 239 is such that it will cause piston 236 to move upwardly before the strut piston 22| begins to move toward the left hand. As the locking piston 236 is moved upwardly by spring 236, the lever 24| is rotated and acts through the link 243 to pull the roller 244 into locking engagement with surfaces 226 and 245. Then, when the pressure in the strut piston chamber 225 is reduced sufficiently, the pressure of spring 229 returns the strut piston 22| to its extreme left hand or normal position, and in so doing, operates the stem 222, lever 223, tie rod 232 and bell crank lever in such a manner that positioned the roller 234 is lifted out of engagement with the car spring plank 235.

With the roller 244 in locking engagement with surfaces 220 and 245 and the strut piston 22| returned to its normal position, as above described, the outward pressure of the limiting valve spring 2|3 acting upon plunger 2M., screw 2|5 and arm 2I6 will not aiiect the adjustment of said spring.

When the pressure in piston chamber 21|] is reduced sufciently, the pressure of spring 21| moves said piston and thereby the double beat valve 263 to their right hand or normal position, as shown in the drawings, and in this position, the piston chamber 262 is connected through passage 265, chamber 261| and p-ast the double beat valve 263 to chamber 266 which is connected to a pipe 213 leading to chamber |85 in the electric brake controlling valve device i and to the piston chamber |88 in the relay valve device 5.

The double check valve device 1 is provided for controlling communication between the relay valve device 5 and the brake cylinders I3, and the variable load mechanism 6 and said brake cylinders, and comprises a casing containing a piston valve 219 having at one side a chamber 215 connected to a pipe 216 leading to valve chamber |9| of the relay valve device, and having at the opposite side va chamber 211 connected to a pipe 218 leading to diaphragm chamber 2|@ in the variable load mechanism 6. A volume reservoir 219 is connected to the pipe 218. The double check valve device is also provided with a passage 280 connected to a pipe 28| leading to the brake cylinders I3, and adapted to be connected to chambers 215 and 211, according to the position of the piston Valve 216.

One terminal of the battery I is connected to a wire 282 which is connected to the movable contacts 66 and 6 1 of the toggle switches on the combined brake valve and brake switch device I, while the other terminal of the battery is connected to a return wire 283 which extends through the train and to which is connected all of the magnets 96, 91, |12 and |88. The fixed contacts 6| and 68 of the toggle switches are connected to an application wire 284 and a release wire 285, respectively, which wires extend through the in parallel to the application wire 284, and the in parallel to the application wire 289, and the magnets 91 and |12 are connected in parallel to the release wire 285.

In operation, when the combined brake valve and brake switch device is in the release posi, tion, as shown in Figs. l and 2, the toggle switches are open, and consequently, the circuits to all magnets in the train are open and the magnets deenergized.

In the release position of the combined brake valve and brake switch device I, the cam I9 is positioned, as shown in Figs. 1 and 3 of the drawings, to permit spring 43 to seat vent valve 40, the cam 11 is positioned, as shown in Fig. 1 of the drawings, to permit spring 18 acting on collar 19 to maintain fulcrum rod 13 and therefore lever 1| in the innermost position, and the cam 39 is to hold member 26 in its outermost position, as shown in Figs. 1 and 5 of the drawings.

When the cam 39 and therefore fulcrum member 26 are positioned as above described, the brake pipe discharge valve i1 is seated upon its seat in abutment 2| against the opposing pressure of spring 22, and the brake pipe charging valve I6 is unseated against the opposing pressure of spring 26.

Fluid. under pressure is supplied to the main reservoir 8 in the usual, well known manner. Fluid under pressure from the main reservoirI flows to the main reservoir pipe 9 which extends through the train, and from said pipe fluid under pressure flows to the feed valve device I and the pneumatic brake controlling valve device 3. The feed valve device Ill operates in the usual manner to reduce the pressure of fluid supplied from the main reservoir to the pressure desired to be carried in the brake pipe |5, and to supply fluid at this reduced pressure to the brake pipe charging valve` chamber I8, by way of passage I9. From chamber I8 fluid at feed valve pressure flows past the charging valve I6 to chamber I4 and from thence to brake pipe I untilthe brake pipe is charged with fluid at the pressure suppliedl by the feed valve device l0.

The pressure of fluid thus obtained in chamber ill acts upon the movable abutment 2| and moves said abutment towards the left hand against the pressure of the regulating spring 23. This movement of the abutment 2| relieves pressure on one end of the beam 21 'which Vpermits the pressure of spring 29 actingthrough the charging valve. |6 on the other end of said beam, to move said charging valve toward its seat. The pressure of spring 23 is preferably so adjusted with respect to the pressure supplied by the feed valve device I9 however, that when the pressure in chamber Ill and brake pipe |5 is increased to the degree supplied by the feed valve device, the abutment, 2| ceases moving toward the left hand in a position in which the charging valve I6 is still partially unseated. By this construction, the feed valve device I0 acts to maintain the pressure in brake pipe I5 against leakage, when the brakes are released.

Fluid under pressure supplied to the brake pipe= I5 flows to passage |26 in the pneumatic brake controlling valve device 3, and through said passage to the vent valve chamber |5|, and from said passage through passage |38 to chamber |31 which is open to piston chamber |25 of the service valve device |29, and from chamber |31 through passage |36 to piston chamber |35 of the emergency valve device |2l.

With the parts of the service valve device |20 in the release position, as shown in the drawings, fluid under pressure flows from chamber |25 through a feed groove 286 to valve chamber |21 and from thence through passage |28 to pipe |29 leading to the auxiliary reservoir I2, thereby charging said auxiliary reservoir. Fluid at the pressure in the auxiliary reservoir i2 flows from passage |28 to a pipe 281 leading to the applica-1 tion valve chamber |98 in the relay valve device 5, and from said chamber through the restricted, passage 294 to chamber |91 at the spring side of the application valve |96. With the applica tion piston |81 in the normal or brakes released position, as shown in the drawings, the springs 209 and 262 in addition to the pressure of fluid in the spring chamber |91 acts to hold the application valve |96 and pilot valve |99 against the seat ribs 29| and 203, respectively.

`With the service valve device in the release position, just described, chamber 211 at the left hand side of the piston valve 214 in the double check valve device 1 is vented to the atmosphere along with the volume reservoir 219 by way of pipe 218, diaphragm chamber 2| 9, passage 2159, and past the ball valve 254 in the variable load mechanism 6 to pipe 288 leading to passage 289` in the pneumatic brake controlling valve device 3, and from said passage through a choke plug having an opening 299 for controlling the rate of release of brakes, to a passage 29|, and from thence through a cavity 292 in slide valve |39 to an exhaust passage 293 leading to thevatmosphere.

With the parts of the emergency valve device |2 in the normal or release position, as shown in the drawings, fluid supplied from the brake pipe to passage |36 flows through a passage 294 to the seat of slide valve |42, and from said passage through a port 295 in said slide valve and a registering passage 296 in the auxiliary slide valve |43 to chamber |41 which is open to valve chamber |39. Fluid thus supplied to chamber |39 flows through passage |49 to the quick action chamber |4| thus charging said chambers to brake pipe pressure.

With the emergency valve device |2| in the release position, the vent valve piston chamber |54 `and the high pressure valve piston chamber |66 are both vented to the atmosphere by way of passage |55, port 291 in the emergency slide valve |42, cavity 299 in the auxiliary slide valve |43, port 299 in said slide valve |42 and exhaust passage 399 which leads to the atmosphere.

With the vent valve piston chamber |54 vented to 'the atmosphere, the vent valve |59 is held seated by the combined pressures of spring |52 and uid from the brake pipe in chamber |5|, while with the high pressure valve piston chamber |66 vented to the atmosphere, the high pressure valve |69 is held seated by the combined pressures of spring |63 and uid at main reservoir pressure which is supplied from the main reservoir pipe 9 to chamber |6| by way of passage |62.

Fluid under pressure from brake pipe I5 flows to the electropneumatic control device 2, and through a passage 39| in said device to the seated area of the application control valve 94 outside of seat rib |99, and from thence through passage 392 to chamber I9. With the application control magnet 96 deenergized, spring holds the double beat valve |94 seated in its upper position, so that fluid flows from chamber ||9 to chamber |95 and from said chamber through passage 393 to chamber 99 at the spring side of the application control valve 94, which valve is thus held seated against seat rib |99 by the combined pressures of fluid and spring 99 .in chamber 98.

With the release control magnet 91 deenergized, the valve ||6 is seated and the valve H3 is unseated due to the action of spring H9. With the valve |3 unseated, the chamber |9| at the spring side of the release control valve 95 is vented to the atmosphere Ithrough passage 394-, chamber H8, past the valve H3 and through the atmospheric exhaust passage H5, and as a consequence, the piston chamber 89, in the combined brake valve and brake switch device i, and the timing reservoir 9| are both at atmospheric pressure, being vented through pipe 395 and the slight clearance space provided between the release control valve 95 and the casing, to the vented chamber |9|.

Fluid under pressure is supplied from the brake pipe I5 to chamber |84 in the electric brake controlling valve device 4. Both the application magnet |89 and release magnet |12 of this device are normally deenergized, which permits spring |96 to seat Valve |83 and unseat valve |8|, and spring |18 to unseat valve |13. With these valves in this condition, the relay valve piston chamber |85 and the variable volume chamber 262 ci the variable load mechanism 6 are both vented to the atmosphere by way of pipe 213, chamber |95, past the unseated valve IBl, through passage 396 to chamber |11, thence past the unseated valve |13, through chamber |14 and to the atmosphere through the exhaust passage |15.

When the relay valve piston chamber |89 is thus open to the atmosphere, the piston |81 and the exhaust valve |93 assume the release position, as shown in the drawings, in which position the valve chamber |9| is vented to the atmosphere through a port 391 in said exhaust valve and past one end of said exhaust valve to a passage 398 leading to the atmosphere. Chamber 215 at the right hand side of the check valve piston 214, being connected through pipe 216 to the valve chamber |9| of the relay valve device 5, is thus normally vented to the atmosphere, and if the double check valve piston 214 is in the position shown in the drawings, the brake cylinders i3 are also normally vented to the atmosphere by way of the relay valve device 5 since said cylinders are connected through pipe 28| and passage 229 in the double check valve device to the ventedI chamber 215. If the double check valve 214 is in its right hand position, then passage 289 is open to chamber 211 and therefore vented by way of said chamber through the variable load mechanism 6 and service valve device |29 in the manner hereinbefore described.

With Ithe brake system fully charged with fluid under pressure, and with the brakes released and' the variable load mechanism 6 properly adjusted for the load on the car, as above described, if it is desired to eect a service application of the brakes, the handle 38 of the combined brake valve and brake switch device is moved from the release position into the service zone. It will here be noted that in the service Zone of handle 38,

the apparatus operates to apply the brakes elec tropneurnatically, as well as purely pneumatically, the latter operation being eiiective only in case the electropneumatic operation fails, however, as will be more fully described hereinafter.

Upon movement of the handle 38 into the service Zone, the cam 11 is turned and acts through the roller 16 to move fulcrum rod 13 and lever 1| outwardly toward the right hand a distance depending upon the degree of movement of said handle into the service zone. During this move ment of rod 13, spring 93 acts to hold the automatic lapping piston 86 in a fixed position, so that the lever 1| turns in a clockwise direction about the pin 88.

The lever 1| in turning clockwise about the fulcrum pin 88 first engages the collar 95 on the toggle switch contact operating rod 3i and turns the switch arm 65 in a countercloclrwise direction about the pin 66 until the spring 69 acts on the opposite side of said pin when said spring acts to snap the contact 61 into engagement with fixed contact 68, thereby connecting the positive terminal of the battery through wire 282, contacts 61 and 68 and wire 3|| to the release train wire 295. At substantially the same time as the toggle switch arm 95 is operated as just described, the 1ever.1| engages the collar 83 on the operating rod 89 and operates said rod to turn the con-- tact arm 58 in a clockwise direction about the pin 59 until the spring 62 acts on the opposite side of said pin and snaps the contact 59 into engagement with the xed contact 6| thereby connecting the positive terminal of battery to a wire 3|2 leading to the application train wire EN This circuit closing position of the toggle switch arms 53 and 55 is shown in Fig. 7 of the drawings.

The release magnet H2, being connected across the release train wire 295 and return train wire 283, which leads to the negative pole of battery |I, is energized when the toggle switch contact 6l engages contact 68 and consequently operates to seat the valve H3, while the application magnet |96, which is connected across the applicau tion train wire 281i and return wire 283, is energized when the toggle switch contact 69 engages contact 6|, and consequently operates to seat valve |8| and unseat valve |83.

The unseating of valve |83 permits iluid under pressure to ilow from brake pipe i5 through chamber It to chamber |85 and from thence through pipe H3 to the variable load chamber 262 and relay valve application piston chamber |88.

The pressure of fluid thus supplied to the application piston chamber |98 moves the piston |81 towards the right hand which rst shifts the exhaust valve |93 on its seat to lap the atmospheric exhaust pasage 398. Upon further movement of the application piston |81, the end of the piston stem |99 first engages and unseats the pilot valve |99 and then engages and unseats the application valve Hit. The unseating of the pilot valve |99 is adapted to vent fluid under pressure from chamber |91 at a rate exceeding the rate of supply through-the restricted passage 291|, and thereby reduce the seating pressure on the application valve, so that after the pilot valve |99 is unseated a slight increase in the pressure in chamber l 88 will operate the application piston |81 to unseat the application valve.

With the application valve |95 unseated, fluid flows from the auxiliary reservoir i2 through pipe |29, passage |28 in the pneumatic brake controlling valve device 3, pipe 28|, chamber |98, past the application valve to chamber |9| and from thence through pipe 2'56 to chamber 215 at the right hand side of the double check valve piston 2M. The pressure of fluid thus obtained in chamber 215 is adapted to shift the double check valve 2M to its left hand position and thereby establish communication from said chamber to passage 29@ through which fluid from the auxiliary r-eservoir is adapted to ow to pipe 28| and from thence to the brake cylinders i3 and thereby apply the brakes.

The release control magnet 97 and application control magnet 965 are connected to the same respective train wires and are adapted to operate simultaneously with the release magnet |172 and application magnet |89. The energization of the release control magnet 9| seats valve H3 and unseats valve il@ thereby connecting chamber at the spring side of the release control valve 95 through passage 334, chamber HB, past valve I6 to chamber and from thence through passage 3|5 to the opposite side of said control valve outside of seat rib |23 and to the face of the application control valve 9d within the seat rib |99. The energization of the application control magnet 96 shifts the double beat valve |94 to its lower seated position thereby closing communication between the opposite sides of the application control valve 94, and at the same time venting fluid under pressure from chamber 98 at the spring side of said application control valve through passage 393, past the double beat valve |95, to chamber lill and from thence to the atmosphere through passage H18.

With the spring chamber 93 vented to the atmosphere, fluid at brake pipe pressure acting on the opposite face of the application control Valve, outside of the seat rib |69, moves said valve away from the seat rib it, against the opposing pressure of spring 99, and thereby establishes a communication through which fluid from the brake pipe l5 flows past said Valve to passage 3|3 and from thence through pipe 395 to timing reservoir 9| and chamber 89 at the left hand side of the lapping piston 3S. Fluid under pressure from passage 3|3 also flows past the unseated release valve I6 to chamber |8 and from thence through passage 304 vto chamber |l| at the upper side of the release control valve 95 so as to equalize the fluid pressures acting on the opposite sides oi' said release control valve and thereby permit spring |02 to maintain said valve in engagement with seat rib |93.

The pressure of fluid thus obtained in the timu ing reservoir 9| and chamber $9 moves the piston 85 against the opposing pressure of spring 93 and thereby rotates the lever 'il about the pin 'l2 thereby causing said lever to first engage with button 82 on the rod Si) and then pull said button and rod toward the left hand thereby rotating the Contact arm 58 in a counterclockwise direc tion until the action of spring 62 is in a line on the left hand side of the pivot pin 59, at which time the contact arm and contact Sii are snapped to their normal or open circuit position. This operation pulls the contact @t away from contact 6| and thereby opens the circuit to the application train Wire 284 and consequently causes deenergization of the application control magnet 96 and application magnet |89.

The deenergization of the application control magnet 96 permits spring to seat the double beat valve IM in the upper position, which permits fluid under pressure to equalize from the seat side of the application control valve f through passage 392, chambers H9 and |95 and passage 393 into chamber 93 at the spring side of said valve, whereupon spring 99 shifts said valve into engagement with seat rib i9@ to close communication from the brake pipe passage to passage 3|3 leading to the timing reservoir, so that the supply of fluid to said reservoir and the lapping piston chamber |39 is cut oi and the fluid under pressure in said reservoir and cham* ber is bottled up. As a result, the movement y the lapping piston 86 ceases upon the cessation of the increase in pressure in chamber 89, and this occurs immediately following the operation of lever l'l and the toggle switch arm 58 to move contact |59 away from contact 6| to open the application train wire circuit.

When the application magnet |89 is deenern gized by operation of the lapping piston 85 as above described, spring |89 seats valve |83 and thereby cuts off the supply of iluid from brake pipe l5 to the application piston chamber |33 and variable load chamber 262. The valve |8| is unseated upon the seating of valve |83 and opens communication from chamber |25 to chamber |82 which is connected through passage 3&6 to chamber but with the release magnet |l2 energized and valve |13 seated iluid under pressure is bottled up in the application piston chamber |88 and variable load chamber 252.

As fluid under pressure is supplied from auxiliary reservoir i2 by way of the relay valve device 5 and double check valve device to the brake cylinders |3 .,iluid flows from passage 216 in the relay valve device through a passage containing a restriction 3M to chamber |89 at the L the right hand side of the application piston |81, and the consequent build up of pressure in chamber |88 is just slightly behind the build up of the control pressure in chamber |88, so that while the relay valve device is supplying iiuid under pressure to the brake cylinders I3, the piston |81 will maintain the application valve |88 unseated. After the supply of iiuid to the control chamber |88 is cut ori and the iluid under pressure therein bottled up, as above described, the piston |81 maintains the application valve |98 open until the pressure in chamber |89 is increased to a degree sucient to overcome the control pressure in chamber |88, at which time the application piston |81 is moved towards the left hand and permits springs 288 and 282 to seat the application valve |85 and pilot valve |89 and thereby cut on the supply of fluid to the brake cylinders i8. The whole equipment is now in lap condition.

It will be noted, upon an inspection of Fig. 2 of the drawings, that the combined brake Valve and brake switch device E is of the type having a service Zone, and when the handle 38 is moved to any position in said Zone, a service application of the brakes will be obtained in the manner above described, the degree of application varying according to the position to which the handle is moved, the maximum service application being obtained when the handle 38 is moved to the extreme right hand end of the zone.

If the application of brakes effected in the manner above described is less than the maX- imum or full service application, then in order to increase the degree or application, the handle 88 is turned further towards the right hand, as viewed in Fig. 2 of the drawings, according to the degree of increase in brake application desired.

This further movement of the handle38 operates the cam 11 to move the iulcrum rod 13, and thereby the pin 12 upon which the lever 1| is fulcrumed, further towards the right hand. At this time the position or" the lapping piston 86 is Xed by the opposing and equal pressures of spring 88 and iiuid in chamber 89 so that the lever 1| fulcrums on pin 88 and consequently operates the application toggle switch arm 58 to again connect the positive terminal of battery l! to the application train Wire 284, whereupon the application magnet E88 is again energized and operates to supply fluid under pressure to the application piston chamber |88 and variable load chamber 282 and thereby cause the relay valve device e to operate and supply fluid under pressure to the brake cylinders I3 to increase the degree of application. The reenergization of the application control magnet 88 causes the application valve 88 to again open to increase the pressure in timing reservoir 8| and lapping piston chamber Qyvhereupon the lapping piston is again moved toward the right hand against the opposing and increasing pressure of spring 88 until the toggle switch arm 58 is again operated to open the circuit to the application train wire 288 and thereby cause the apparatus to again operate to lap the brakes.

The brake system may be operated in the manner above described to graduate on an application of the brakes in such increments as desired,

or if desired, the handle 88 may be moved to the extreme right hand end of the service zone, as viewed in Fig. 2, and the maximum service application of the brakes will be obtained in a single step.

In order to release the brakes electrically, after an application, the handle 88 is moved toward the left hand, as viewed in Fig. 2. This turns the cam l1 in such a direction as to permit spring 18 acting on the collar 18 of fulcrum rod 13 to move said rod and the pin 12, upon which lever 1| is iulcrumed, toward the left hand. Since at this time the lapping piston 86 is held in a fixed position by the opposing and equal pressures of spring 83 and fluid in chamber 88,

the lever 1| pivots on pin 88 and turns in a counterclockwise direction. With the brake system in lap condition the toggle switch arm 58 is in the circuit open position, so that the turning of lever 1| engages button 88 on rod 8| and pulls said rod and acts to turn the release toggle switch arm 85 in a clockwise direction about the pin 88. As soon as the line of action of spring 88 is thereby transferred to the left hand side of pivot pin 88, said spring cts to snap the arm 85 to its normal position, as shown in Figs. 1 and 6. This moves contact 81 out of engagement with contact 88 thereby opening the circuit to the release train wire 285 and through the release magnet |12 and release control magnet 81.

The consequent deenergization of the release magnet |12 permits spring |18 to unseat valve 13, and with the application magnet |80 deenergized, fluid under pressure is released from the application piston chamber l88 and variable load chamber 282 by way of pipe 213, chamber |85, past valve |8|, through chamber |82, passage 308, chamber |11, past valve |13, through chamber |14 and to the atmosphere through passage |15.

The consequent reduction in pressure in the application piston chamber |88, permits brake cylinder pressure acting in chambers |88 and |8| to move the application piston |81 toward the left hand and thereby shift the exhaust valve |88 so as to open communication from valve chamber |9| through port 881 in said exhaust valve and past the end thereof to passage 388 leading to the atmosphere. With the exhaust valve |83 in this position, fluid under pressure is released from the brake cylinders |3 through pipe 28|, passage 288 and chamber 215 in the double check valve device, and from said chamber through pipe 218, valve chamber |S| and atmospheric passage 388, thereby releasing the brakes.

The deenergization of the release control magnet 91 permits spring H8 to seat valve ||6 and unseat valve H 3 which permits venting of fluid under pressure from the chamber at the spring side of the release valve 95, by way of passage 88d, chamber H8, past the valve ||3 to chamber H8 and to the atmosphere through the atmospheric exhaust passage M5. When the pressure of fluid in spring chamber |8| is thus reduced suiiiciently, iiuid at the pressure in timing reservoir 8| and chamber 88, acting on the lower face of the release valve 85 outside of seat rib |88, moves the release valve away from the seat rib E88 and thereby establishes a communication between passage 8|3 and an atmospheric exhaust passage 3|5, through which fluid under pressure is released from said reservoir and said chamber.

As the pressure of fluid in chamber 88 is thus relieved on the lapping piston 88, spring 83 moves said piston toward the left hand and consequently rotates lever 1! in a clockwise direction about the fulcrum pin i2.

If" the handle38 and therefore fulcrumrod 54 is reduced to a degree slightly lower thanthe 13 andA pin 12 are returned' to the release or normal position, then the clockwise rotation of lever 1| ceases, when the lapping piston 96 assumes itsnormal position, and at just about the time said lever engages the collar 85 on the rod 8|, so that the toggle switch' arm 65 remains in itsnormal circuit opening position, and the release magnet |12 and release control magnet 91 remain deenergized so as to permit a complete release of brakes and a complete venting of 'fluidVV under pressurel fromy the timing reservoir 9| and piston chamber 89. This venting of fluid from timing reservoir 9| and piston chamber 89 occurs through the atmospheric eX- haust passage 3|5, as hereinbefore described, until the pressure of fluid' acting on the lower face of the release valve 95, is overcome by the relatively light spring |92-, then said spring moves said valve into engagement with seat rib |93', after which, the slight pressure still remaining in said reservoir and chamber is dissipated throughthe clearance spacebetween said valve and the casing, to chamber' ||l| andr from thence wthrough passage 394, chamber ||8, past valve ||3I and through the atmospheric passage ||5.

If instead of permitting a continuous and complete release. of brakes after an application,

as above described, it is desired to graduate the release of brakes, then the handle 38 is moved towardl release position to someA position in the service zone depending upon the deg-reey of release of brakes it is desired to effect. 'I'his ymovement ofk handle 38 and the consequent movement of the fulcrum rodv 13 towards thevleft hand: causes a release of fluid under pressure from the brake cylinders I3 and: timing reservoir 9|. and piston chamber 89, in the same manner as hereinbefore de- '1t-rod and thereby turn thefrelease toggleswitch contact arm 65 in a counterclockwise direction until spring 69 snaps the contact 61 intoengagement with contact 68- thereby energizing the release train wire 28,5.and consequentlythe ref', lease control magnet-91 and releasefmagnetl |12.

The energization of the release control magnet 91 seats valve ||3 and unseats valve I6 so as to supply uidj'under pressure from the timing reservoir 9| through pipe 395, passage 3| 3, chambers ||1 and i8 and through passage 394 to chamber ||l| at the spring side of the release valve 95. The fluid pressures are thereby equalized ontheopposite sides of the release valve 95, and spring |02 moves said valve into engagement with seat-rib |93 so as to prevent further reduction in pressure-iny said timing reservoir and chamber 89, and consequently prevent further movement of the piston 86 toward the left hand.

The energization of the release magnet |12 :seats valve |13 so as to prevent further venting of uid under pressure from the application piston chamber |88 of the relay valve device 5 and from the connected variable loadvolume 262. When the brake cylinder pressure in valve chama ber |9| 'and chamber |89 of the relay valve device bottled pressure in the applicaton piston chamber |88, the application piston |81 is operatedY to move the exhaust valve |93toward-the right hand and lap the atmospheric vent passage 388 so as to prevent further venting of fluid under pressure from the brake cylinders i3. Theapparatus now is in a lap condition in which a partial application of the brakes is held effective. v

If now it is desired to further reduce brake cylinder pressure, the handle 38 is moved further toward the release position, whichpermits spring 18, to move the fulcrum rod 13 inwardly and thereby turn the lever in a counterclockwise direction about pin 88 to again operate the toggle switch arm 65 to open the circuit through the release train wire 285 and cause deenergization of the release control magnet 91 and release magnet |12. This permits a further venting of fluid from the brake cylinders I3 until the timing reservoir and toggle switch arm 65 to energize the release control magnet 91 and releasemagnet |12 to again lap the brakes.

By moving the handle 38 through the service zone to the release position in a series of suc-f cessive stages, the apparatus will operate, as above described, to graduate off or provide a series` of successive reductions in pressure in the brake cyl-` inders |3 in accordance with the position of said crease of pressure in the timing reservoir 9| .and lapping piston chamber 89 as controlled by the operation of the application control valve 94and release control valvexl.V-l y i j ,Y

The-application magnet |89and release magn et |12 operate in synchronism with the application control magnet 96 and release control mag.- net 91, respectively, so that during the period of time iiuid under pressure is being supplied toor released from the timing reservoir 9| and lapping piston chamber 89, fluid under pressureisY being simultaneously supplied to or released fromr the variable load chamber 262 and the application piston chamber |88 of the relay valve device 5, thereby causing corresponding variations in pressure in the brake cylinders I3.

ngotherfwords, the pressure obtained in the variable load chamber 262 and application lpiston chamber |88 and therefore in the brake cylinders i3 dependsupon the time required to effect a suflicient change in pressure in the timing reservoir 9| and lapping piston chamber 89 to permit operation of the toggle switch arms 58 and 65 according to the position of the handle 38 and therefore the pin 12 upon which the lever 1| is fulcrumed.

Since the volume of the variable load chamber 262 depends upon the load carried by the car and is increased upon a reduction in the load, and is decreased upon an increase in the load, it will be evident that the pressure obtained therepressure is again reduced sufficiently to permit the lapping piston 86 to again operate leverl1|- in and in the application piston chamber |88 of and lapping piston chamber 89 is being eiected, will be greater for a heavy load than for a light load, or, in other words, will be proportional to the load carried by the car regardless of the degree of application as governed by the position of the brake valve handle.

When the handle 38 is moved into the service zone to effect a service application of the brakes electropneumatically, as above described, the cam 39 is also simultaneously turned in a counterclockwise direction, as viewed in Fig. 5 of the drawings. This relieves the pressure of cam 39 on the fulcrum member 26 and permits said member to move toward the right hand and the beam 21 to turn clockwise due to the action of spring 20 which urges the valve I6 to its seat to cut off the supply of fluid from the feed valve device I to chamber I4 and from thence to brake pipe I5. As the cam 39 is turned further, pressure is relieved from the brake pipe discharge Valve stem 32 which permits spring 22 to move the discharge valve I1 away from its seat in the abutment 2|.

The unseating of the brake pipe discharge valve I1 permits fluid under pressure to flow from the brake pipe I5, through chamber i4, past the brake pipe discharge valve I1 to spring chamber 24 and from thence to the atmosphere through the atmospheric exhaust passage 25.

As the brake pipe pressure is reduced in chamber I4l on the movable abutment 2|, the regulating spring 23 moves said abutment toward the right hand. With the handle 38 and therefore cam 39 in a certain position in the service Zone, l

fluid continues to be vented from the brake pipe I5 until the movable abutment 2| moves into engagement with the discharge valve I1 to prevent further venting.

If the handle 38 and therefore cam 39 are turned from release position only part way through the service zone, then the degree of reduction in brake pipe pressure eiected past the discharge valve I1 is limited to less than a full service reduction. In such a case, if it is desired to increase the degree of brake pipe reduction, the handle 38 and cam 39 are turned further through the service zone in a counterclockwise direction, as viewed in Figs. 2 and 5 of the drawings. Ihis action further relieves the pressure on l the fulcrum member 26 which permits spring 22 to unseat the discharge valve I1 and effect a further reduction in brake pipe pressure, such reduction being limited by the regulating spring 23 moving the abutment 2| into engagement with the discharge valve I1.

From the above description it will be noted that the movable abutment 2| cooperates with the brake pipe discharge valve I1 to reduce brake pipe pressure a degree depending upon the movement of the handle 38 from release position into the service zone, and this movement may be either effected in a single movement or in a series of successive stages to eiTect a continuous or graduated reduction in brake pipe pressure, as desired.

The venting of fluid from the brake pipe I5 by way of the brake pipe discharge valve I1 causes a reduction in pressure on the face of the application control Valve 94 and in the application magnet valve chamber I 84, but such reduction in pressure on said valve and in said chamber in no way interferes with the simultaneous operation of the electropneumatic apparatus in effecting a service application of the brakes. The venting of fluid from the brake pipe I5 also causes a service reduction in pressure in the service valve piston chamber |25, but the piston |24 does not respond to such reduction when the application of brakes is being effected electropneumatcally, since at the same time as the pressure is being reduced in the chamber |25, the auxl iliary reservoir pressure acting in valve chamber |21 is being reduced by ow past the application valve |96 to chamber |9| in the relay valve device 5 and from thence to the brake cylinders I3 at such a rate as to prevent obtaining sumcient differential of pressures on piston E24 to move said piston.

1f, however, when the handle 38 is moved into the service zone, and the brakes fail to apply electropneumatically in the manner hereinbefore described, such failure being due possibly to the failure of electric supply such as battery I I, thenA the service reduction in brake pipe pressure in piston chamber |25 of the service valve device |20 causes the piston |24 to move upwardly t0 service position which is defined by the engagement of said piston with a gasket BIB. During this movement of piston |24, the auxiliary slide valve I3I is first shifted to uncover a service port 3 I 1 in the main slide valve |30 and then said main slide valve is moved to service position in which service port 9I1 registers with a passage 3|8. With the slide valves |30 and |3| in this service position, uid under pressure supplied from the auxiliary reservoir to valve chamber |21 ows to passage 3|8 and from thence through a restricted port 3I9 in a choke plug to passage 289, then through said passage and pipe 288 to the variable load mechanism 6. Fluid thus supplied to the variable load mechanism flows past the ball valve 254 and through chamber 248 to passage 249 and from thence to the limiting valve diaphragm chamber 2I0, and at the same time as iluid thus flows past the ball valve 254, iluid under pressure also flows from passage 288 past the limiting valve 289 to chamber 2I0, from Whence'fluid flows through pipe 218 to the volume reservoir 219 and to chamber 211 at the left hand face of the double check valve piston 214. When the electropneumaticA apparatus is ineifective, the chamber 215 in the double check valve device is vented to the atmosphere through the relay valve device, so that fluid under pressure supplied to chamber 211 shifts the piston 214 to its right hand position and thereby opens conn munication from chamber 211 to passage 280, through which communication, fluid flows to pipe 28| and from thence 'to the brake cylinders I3, thereby applying the brakes.

In case the reduction in brake .pipe pressure effected by the brake pipe discharge valve I1 is less than a fullservice reduction, then when the auxiliary reservoir pressure in valve chamber I 21 becomes reduced by flow through the service port 3|1 to a degree slightly lower than the brake pipe pressure in chamber |25, the differential of these pressures acting on piston |24 acts to shift said piston and auxiliary slide valve ISI to lap the service port 3I1 and thereby prevent further ilo-vv of fluid under pressure from the auxiliary reservoir. If a further reduction in brake pipe pressure is then effected the service piston is again moved to service position to permit a corresponding further reduction in auxiliary reservoir pressure, the maximum service reduction in brake pipe pressure and therefore in auxiliary reservoir pressure being limited by either equalization of auxiliary reservoir pressure into the brake cylinders I3 as may occur in case of a fully loaded car, or by the closure of the limiting Valve 209 in the variable load mechanism 6 so as amm-,1s

speen to ,the pressure of fnud. supp1ied.;by.,sa1d

` to prevent further flow ofuidffrom the auxiliary feed valve device, that when fullfeed valve reservoir I2 to the brake cylindersas incase Lthe car is less than fully loaded, as will ,be hereinafterdescribed.

When the pressure obtained in the brake cylinders I3 and acting on Amovable abutment 241 of the variable load mechanism exceeds the opposing pressure of spring 25|, said abutment moves downwardly which permits spring 255 to seat valve 25H and out ofi further iiow of fluid pastsaid valve. This valve 254 and itsspring 255 are provided to permit a limited minimum application of brakes in case the :limiting valve 289 should at any time -fail to be normally in Athe unseated condition.

After the Valve 254 is seated-huid under pressure continues to flow-to vthe brake cylinders AI3 by way of passage-288 pastthe limiting valve H yand through diaphragm chamber 2|!) so long as fluid is suppiied by the service valve-device |23 or until the brake cylinder pressure acting in saidchamber on the diaphragm 2|| overcomes vthe opposing pressure of the regulating spring chamber I 39 to move-said piston and the auxiliary `slide valve M3 outwardly to service position in which uid under pressure is permitted to flow from valve chamber |39 and the connected quick action chamber MI, through a service port 32E) in the auxiliary slide valve |43, and port 299 in the main slide valve |32 to atmospheric passage 303, at the same rate as the brake pipe pressure is reduced,v thereby preventing further movement of said piston outwardly. When the pressure in valve chamber |39 is thus reduced to a degree slightly below the reduced brake pipe pressure in piston 'chamber' |35, said piston is operated to return the auxiliary slide valve |43 to its normal position and thereby close communie-ation from the service port 320 to port 239 so as to prevent further venting of fluid from the valve chamber |39.

In order to release the brakes after an application eifected pneumatically in the manner above described, the handle 3B is turned to the release position and the cam 39 is consequently returned to its normal position, as shown in Fig. 5 of the drawings.

The turning of cam 33 to its normal position moves the fulcrum member 26 and the pivot pin 28 carrying the beam 21 toward the left hand, and with the brake pipe discharge valve l1 seated, the beam 21 acts through the push rod 29 to unseat the supply valve I6 Aagainst spring 23. With the supply valve I6 unseated, fiuidis supplied from the feed valve device I0 to chamber I4 and from thence to brake pipe I5, thereby charging said brake pipe to the pressure of fluid supplied by said feed valve device. As the brake pipe pressure increases in chamber I4, said pressure acting on the abutment 2| moves same toward the left hand against the opposing pressure of the regulating spring 23, and such movement acts through the beam 21 to permit spring 2 to move the supply valve IS towards its seat, but the vregulating spring 23 is so adjusted Withrepressure is acting in chamber |11 on abutment-2 saidabutment will beso positioned as to-v maintainlthe supply valve i6 slightly unseated.

The increasefinbrake pipe pressure in piston chamber |25 of the service valve device shifts piston |26 and slide valves V|30 and IBI to the release position in which the auxiliary reservoir i2 is recharged with fluid under pressure from thebrake pipe and in which fluid is vented from `the brake cylinders I3 by way of pipe-28 I, through passage 283 and chamber 211 in the double check valve .device 1, through `pipe 21:8, diaphragm chamber 2li? inthe variable load mechanismt, fromsaid. chamber past the limiting valve 299 to passage 283,.'and at the same time through passage M9 and past theballfvalve'Zl to passage `,and pipe283 and from thence through passage .239, restricted opening :293, passage '291, cavity "292 5in the service valve slide. valve "through: theeXhaust passage'. 293 to the atmosphere. rihe reservoir volume 219.being connected to pipe 21,8 through which uid under pressure is vented from theY rake cylinders I3, fluid under E3B and pressure is alsov released rfrom said reservoir volume upon the release of fluid under pressure from said brake cyiinders.

`When the pressure of fluid from lthe brake cylinders 3 acting in diaphragm chamber2|ll on diaphragm 2| I andin chamber248- on piston2l1 is reduced, as above described, to below` the opposing pressures of springs 2&3 and 25|, respectively,

`said springs act to unseat the valves Y20S audaz-56 f andplace-the apparatus in the release condition;

` Theincrease in brake pipe pressure in the-emergency valve piston chamber '|35 in electing a release-of brakes after a service application, acts to shift piston I 34 and the auxiliary slide valve M3 to the release y.position in which-the valve chamber |39 andquick action chamber MI are charged with fluid to the pressure carried in-the `brake pipe, inthe manner hereinbefore described.

l When a service application of the brakes is effectedelectropneumatically on a short train of Ycars,\the reduction in brake pipe pressure effected by operation ofthe brake pipe discharge valve I1, the application control valve 94and application Ymagnet |88 maybe sufficiently great before y"the vrelay valve device 5 operatesto reduce auxiliary reservoirpressureby supplying uid under pressure from said auxiliary reservoir to the brake Vcyli-nders I3, as to cause the service valve device "|23 to` move to service position and thereby estab- `lish the communication through which fluid under pressure is adapted to be supplied to chamber 211 in thej double check valve device 'I andl from thence to-the brake cylinders, as, when a service order to ensure that such operation will not occur;

the volume reservoir 219 is connected to pipe 218 and is adapted to delay or retard the build up of pressure in chamber 211 of the double check valve device,` due to the supply of fluid under pressure v from the service valve device |28, suliiciently to permit the relay valve device 5 to operate and supply suicient pressure-,to vchamber 215 at the opposite side of thedcuble check valve piston 214 to move said double check valve piston to its left hand position, incase it is not in said posi- -V tion, or to holdsaid double check valve in said position, against the retarded increase in pressure in chamber 211, so that 'the brakes Will be controlled electropneumatically through the operation of the relay valve device 5. The reservoir 219 serves no useful function except as just described.

If it is desired to eiect an emergency application of the brakes, the handle 38 is turned to emergency position which permits operation of the brake pipe supply valve to cut o the supply of uid under pressure to chamber I4 and thus to the brake pipe, and also permits operation of the brake pipe discharge valve |1 to vent iiuid under pressure from the brake pipe at a service rate, in the same manner as when a service application of the brakes is effected. In addition however, the movement of said handle to emergency position turns the cam 49, shown in Figs. 1 and 3, into engagement with stem 48 and unseats the brake pipe vent valve 4U. With the vent valve 49 unseated, fluid under pressure is vented from the brake pipe I5 at an emergency rate through chamber |4, passage 42, vent valve chamber 4|, past said vent valve, through the aperture 45, chamber 4B and from thence to the atmosphere through the atmospheric exhaust passage 41.

This emergency rate of reduction in brake pipe pressure initiated by the vent valve 40 causes a corresponding ratev of reduction in pressure to occur in the service valve piston chamber and emergency valve piston chamber I of the pneumatic brake controlling valve device 3 closest in the train to said vent valve, and the service valve device Aoperates in the same manner as in eiTecting a service application of the brakes to supply fluid under pressure from the auxiliary reservoir I 2 to the brake cylinders I3. The emergency rate of reduction in brake pipe pressure in the emergency piston chamber |35 permits the pressure of fluid in valve chamber |39 to move the piston |34 and thereby the slide valves |42 and |43 to emergency position which is dened by engagement of said piston with a gasket 32|. It will be noted that piston |34 and slide valve |43 do not stop in the service position in moving from release position as when a service application of the brakes is effected due to the inability of service port 32|) to reduce the pressure 1n chamber |39 at the emergency rate of brake pipe reduction eiected in chamber |35.

At the time shoulder |45 on the emergency piston stem |44 engages the left hand end of the main slide valve |42, as the parts of the emergency valve device are moved to emergency position, the port 291 is uncovered by the auxiliary slide valve |43 which permits fluid under pressure` to flow from valve chamber |39 and connected quick action chamber I4| through said port to passage |55, then upon movement of the main slide valve |42 to emergency position, the passage is connected past the left hand end of the main slide valve |42 directly to chamber |39. Fluid under pressure thus supplied to passage |55 flows to the high pressure valve piston chamber |66 and to the brake pipe vent valve piston chamber |54.

Fluid under pressure thus supplied to the brake pipe vent valve piston chamber |54 moves the piston |53 toward the right hand and unseats the vent valve |50 which establishes a direct communication from the brake pipe l5 to the atmosphere through the vent valve chamber |5 I, chamber |58 and atmospheric passage |59, through which communication fluid under pressure is adapted to be completely vented from the brake pipe at an emergency rate for propagating, serially, emergency action through a train in the usual manner.

Fluid under pressure supplied to the high pressure valve piston chamber |59 moves the piston |95 and therefore plunger |665 toward the right hand until valve |19 is seated. This movement of plunger |34 acts to unseat the high pressure valve |69 which permits fluid from the main reservoir 3 to ilovv through the main reservoir ,pipe 9, passage |62, valve chamber |S|, past the high pressure valve |59 to a chamber 322, and from thence through passage 323, past ball check valves 324, and through passage'; to passage 299 to which fluid under pressure is supplied through therestricted opening 3| 9 from the auxiliary reservoir I2 by operation of the service valve device |20'.

Fluid under pressure thus supplied to passage 289 at a restricted rate from the auxiliary reservoir |2 and at a rapid rate from the main reservoir 8 iiows to pipe 283 and from thence through the variable load mechanism 6 and double check valve device 1 to the brake cylinders i3, thereby rapidly applying the brakes.

The degree of pressure obtained in the brake cylinders in effecting an emergency application of the brakes as just described, is limited by the adjustment of the variable load mechanism 6 acccrding to the load on the'car in the same manner as when a service application of the brakes is eiected pneumatically by the operation of the service valve device |20, the diierence between the emergency and service applications residing in the faster rate obtained when an emergency application of the brakes is effected, than when a service application of the brakes is eiected.

Fluid under pressure supplied from the quick action chamber |4| and emergency valve chamber |39 to operate the brake pipe Vent valve piston |53 and high pressure valve piston |65 is gradually vented to the atmosphere through a restricted port 326 in the vent valve piston |53 to chamber |55, and from thence through passage |51, chamber |58 and atmospheric passage |59. When the pressure inV chamber |54 is thus reduced suiciently, spring |52 acts to seat the vent valve |59 so as to permit the brake pipe to be charged when it is desired to effect a release of the brakes, and When the pressure in the high pressure piston chamber |66 is reduced sufciently, spring 63 acts to seat the high pressure valve |99. The size of the restricted port 326 is so proportioned to the combined volumes of the quick action chamber |4| and emergency valve chamber |39 that the vent valve |50 will not be permitted to seat until thebrake pipe |5 is substantially completely vented, and the high pressure valve |69 is not permitted to seat until after the brakes are fully applied. The check valves 324 are provided to prevent leakage of iiuid under pressure from the brake cylinders E3 and auxiliary reservoir I2, after the high pressure valve |59 is seated, by way of passages 289 and 325 to passage 323 and from thence through chamber 322 and past the plunger |64 to chamber |61 which is open to the atmosphere Athrough passage |58.

When the handle 39 is moved to the emergency position to effect an emergency application of the brakes, the toggle switches are operated to eff-ect energization of the release control magnet 91, application control magnet 96, release magnet aorifvl thebrakes Which variesaccording to the extent |72` and applicationmagnet- |80 in .the same manner as `vvhen a service application of the brakes is efiected,vbut the energization of these magnets vaccomplishes no purpose, since .the brake pipe l Iisscompletely` and rapidly vented in emergency Which eliminates the source of fluid under pressure upon which the application magnet |80 deu ,pendstc efectfthe operation vof the relay valve device 5.

In view of the ineffectiveness of the toggle switches and magnets of the apparatus when an emergency application of the brakes is effected, it will kbe evident that an emergency application ofthe brakes will be obtained in the manner above described regardless of whether said magnets arev operative or inoperative.

y In order to effect a release of brakes after an emergency application, the handle 38 is turned to release position which permits spring 43 to seatthe brake pipe `vent valve 40 and Which operates the beam ENv to seat the brake pipe dislcharge valve I1 and unseat the brake pipe supply valve I6. With the tsupply valve unseated, iiuid underpressure is supplied to the brake pipe |5and the parts of the service valve device |20 and emergency yvalve device |2| are shifted to their release position by the consequent increase infbrake pipe pressure. In the release position of the emergency valve device |2l, the quick actionv chamber lill is charged with fluid at brake -pipe pressure, while. in release position of the service -valve device f|20 the auxiliary reservoir |2is charged with fluid under pressure from the brake pipe, and uid under pressure is vented from the brake cylinders I3 by Way of the double ,check vvalve device 1, variable load mechanism 6 and service valve device |20, in the same manner as hereinbefore described.

It will now be noted that according to the invention, a brake equipment is provided which is operative upon movement of the combined brake valve and brake switch device into the service Zone to effect an application of the brakes electropneumatically, but in case the electrically conaccordance With the load on the car. An emergency application of the brakes is obtainable only by reducing thebrake pipe pressure at an emergencyy rate, such application being obtainable at a faster rate than a service ,application is obtained, but the degree is limited according to the yload on the car the same as when a service application of the brakes is effected due to a service reduction in brake pipe pressure.

:While oneillustrative embodiment of the inventionhas been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims'.

Having now described myl invention,`what I ,claim as new and .desire ,to secure by Letters Patent, is: f

1. In a uid pressure brake, the combination l.With amanuallygoperabl'e member, of electroresponsive; means and fluid pressure; responsive ..lreanseachj operative toeffect anu application `of ofvmovement of said memben-,and ymeans for regulatingthe degree With whichthevbrakesare applied, by the operation of bothofsaid-.meana accordingto the load on the vehicle.

2. lIn a brake apparatus, the combination with a valve device having a chamber and operative according to the increase and `decrease inpressure in said chamberto effect varying degrees of vapplication and release of brakes, valve vmeans for. supplying and releasingiuid under pressure to and from said chamber, a variable volume in constant communication with said chamber,

means for decreasing the volume of saidvariable volume upon an increase in car load andfoninf creasing the volume of said variable volume upon adecrease in car load, and mechanism operated Whena car is stopped foroperating said'means toy vary said volume according to the change in car load and for locking said means and `thereby said volume in` an adjusted condition Whenthe car is running.

3. In a brake apparatus, the combination with .a valve device having a-control chamber-andop- .erative according to variations in pressure in ,said control chamber to effectV an application and la release of brakes vaccording tothe degree. of

pressure in said control chamber, a manually movable control member, electroresponsive Vmeans operative to supplyvfluid under pressure to vsaid chamber and to vent fluid under pressure'ffrom said chamber foratime interval depending upon the extent ofmovement of said control member, a volume chamber in constant communi- .cationvvith said control chamber, means operative according to relative movement-between thebody and truck of a car, upon a change in car-load, for increasing the volume of saidvolume chamber upon/a decrease in car load: and

for decreasing the volume of said volume chamber upon an increase in car load, and means forholding the volume chamber in an adjusted condition.

4. In a brake apparatus, the combination with a valve device having a chamber and operative to effect an application and release of the brakes according to the pressure in said chamber, a manually operated means, electroresponsive means operative to supply fluid under pressure to and release fluid under pressure from saidr chamberfor time intervals depending upon the extent of movement of said manually operated means, a volumeA adjusted according to .the -load on the car and in constant communication with said chamber for varying the pressure in said;

chamber according to the load on the car, ymeans including a member for increasing said volume upon a decrease in the car load and for decreasing said volume upon an increase in the car load,

Vvvalve meanscontrolledy by said manually operated ymeansiand.operative to supply and release uid Vrunder pressure for effecting an applicationv and release of brakes, means, including a spring, for limiting the degree of brake application effected bythe operation of said valve means in accordancegvvith the load on the car, means` including almember for increasing .the pressure of said spring upon an increase in the loadf on thecar and for decreasing the pressure of said spring upon a decrease in the load on the car, an element foroperating saidmembers according to 'relative movement between the body and truck ofthe car 'forfadjustinggy said volume andl spring according to theload 0n the car, and means:in'c1udingamy an adjusted condition while the car is running. l

5. In a brake apparatus, in combination, means operative to supply fluid under pressure for applying brakes and for releasing fluid under pressure for releasing brakes, a member movable to any desired position in a zone for initiating the operation of said means, means for effecting the operation of said means to limit the amount of iiuid under pressure supplied by or released by the operation of said means in accordance with the position of said member in said zone, and means for varying the pressure of uid obtained by the operation of the first mentioned means in accordance with the load on the car.

6. In a brake apparatus, in combination, means operative to supply iiuid under pressure for applying brakes and releasing fluid under pressure for releasing brakes, a member movable to any desired position in a Zone for initiating the operation of said means, means operative according to the position of said member in said zone, and other means operable according to the load on the car, the two last mentioned means cooperating to adjust the degree of application or release of brakes in accordance with the position of said member in said Zone and in accordance with the load on the car.-

7. In a brake apparatus, in combination, a manually controlled member movable in a zone for varying the application and release of brakes, means controlled by said member and operative to effect a supply or release of fluid under pressure in amounts corresponding to the position of said member in said zone, for eifecting an application or release of the brakes, respectively, and means for varying the pressure of iiuid obtained by operation of said means, and for thereby Varying the degree of application or release of brakes, in accordance with the load onY the car.

8. In a braking apparatus, in combination, means having a chamber to which uid under pressure is supplied for effecting an application of the brakes and from which iiuid under pressure is vented to effect a release of the brakes, manually controlled valve means operative to control the supply of fluid under pressure to and the release of fluid under pressure from said chamber, and mechanism for varying the pressure of 'fluid obtained in said chamber by the operation of said valve means in accordance with the load on the car, said mechanism comprising means for increasing the volume of said chamber in accordance with the reduction in car load and for decreasing the volume of said chamber in accordance with the increase in car load, means for operating the last mentioned means according to the change in car load when the car is stopped, and means for locking said last mentioned means and thereby said chamber in the adjusted condition when the car is running.

9. In a braking apparatus, in combination, means having a chamber to which fluid under pressure is supplied for effecting an application of the brakes and from which fluid under pressure is vented to eiect a release of the brakes, manually controlled valve means operative to control the supply of iiuid under pressure to and the release of iiuid under pressure from said chamber, and mechanism for varying the pressure of fluid obtained in said chamber by the operation of said valve means in accordance with the load on the car, said mechanism comprising means for increasing the volume of said chamber in accordance with the reduction in car element for locking said volume and spring in load and for decreasing the volume oi 'said cham* ber in accordance with the increase in car load, means automatically operative for operating the last mentioned means according tothe change in car load when the car is stopped, and means automatically operative for locking said last mentioned means and thereby said chamber in the adjusted condition when the car is running.

10. In a braking apparatus, in combination, V a brake cylinder, valve means operative to eiect a supply of fluid under pressure to said brake cylinder, pressure responsive means for limiting the degree of pressure obtained in said brake cylinder by the operation of said valve means in accordance with the load on the car, switch means operative to effect a supply of uid under pressure to said brake cylinder, means adjusted according to the load on the car for Varying in accordance with the load on the car the pressure of fluid obtained in said brake cylinder by the operation of said switch means, a manually operative member for effecting the simultaneous operation of said valve means and switch means,

and means operative when iluid under pressure is supplied to said brake cylinder by the operation of said switch means for rendering said valve means ineffective.

l1. In a braking apparatus, in combination, a brake cylinder, valve means operative to effect a supply of fluid under pressure to said brake cylinder, pressure responsive means for limiting the degree of pressure obtained in said brake cylinder by the operation of said Valve means in accordance with the load on the car, switchY means operative to effect a supply of fluid under pressure to said brake cylinder, means adjusted according to the load on the car for varying in accordance with the load on the car the pressure of fluid obtained in said brake cylinder by the operation of said switch means, a manually operative member for effecting the simultaneous operation of said valve means and switch means, and means operative when iiuid under pressure is supplied to said brake cylinder by the operation of said switch means for closing communication from said brake cylinder to said valve means for thereby rendering said valve means ineffective.

12. In a braking mechanism, in combination, a brake cylinder, two manually controlled means for supplying fluid under pressure to said brake cylinder and for releasing iiuid under pressure from said brake cylinder, pressure exerting means, means operative according to the pressure of said pressure exerting means to limit the pressure of fluid obtained in said brakecylinder by the operation of one of said manually controlled means, a variable volume for regulating the pressure of fluid obtained in said brake cylinder by the operation of the other manually controlled means, means for simultaneously adjusting the pressure of said pressure exerting means and the volume of said variable volume in -accordance with the load on the car, and means for simultaneously locking said pressure exerting means and variable volume in an adjusted condition.

13. In a braking mechanism, in combination, a brake cylinder, two manually controlled means for supplying fluid under pressure to said brake cylinder and for releasing iiuid under pressure from said brake cylinder, pressure exerting means, means operative according to the pressure of said pressure exerting means to limit the pressure of fluid obtained in said brake cylinder by the operation of one of said manually controlled means, a variable volume for regulating the pressure of fluid obtained in said brake cylinder by the operation of the other manually controlled means, an element movable according to a change in the load on the car for adjusting the pressure of said pressure exerting means and the volume of said variable volume in accordance With the load on the car, and a member for locking said element and thereby said pressure exerting means and variable volume in its adjusted condition.

14. In a braking mechanism, in combination, a brake cylinder, two manually controlled means for supplying uid under pressure to said brake cylinder and for releasing iiuid under pressure from said brake cylinder, pressure exerting means, means operative according to the pressure of said pressure exerting means to limit the pressure of fluid obtained in said brake cylinder by the operation of one of said manually controlled means, a variable volume for regulating vthe pressure of fluid obtained in said brake cylinder by the operation of the other manually controlled means, means operative automatically for simultaneously adjusting the pressure of said pressure exerting means and the Volume of said variable volume in accordance with the load on the car, and means operative automatically for simultaneously locking said pressure exerting means and variable volume in an adjusted condition.

15. In a braking mechanism, in combination, a brake cylinder, two manually controlled means operative simultaneously for at one time supplying fluid under pressure to said brake cylinder and at another time releasing fluid under pressure from said brake cylinder, pressure exerting means, means operative according to the pressure of said pressure exerting means to limit the pressure of fluid obtained in said brake cylinder by the operation of one of said manually controlled means, a variable volume for regulating the pressure of uid obtained in said brake cylinder by the operation of the other manually controlled means, means operative to adjust the pressure of said pressure exerting means and the volume of said variable volume in accordance With the load on the car, and means for rendering ineffective the operation of said one manually controlled means when said other manually controlled means is eiective.

16. In a brake apparatus, in combination, a valve device having a chamber and operative according to the increase and decrease in pressure in said chamber to effect varying degrees of application and release of brakes, valve means automatically operative for supplying fluid under pressure to and releasing fluid under pressure from said chamber in predetermined amounts for controlling the operation of said valve device, means for decreasing the volume of said chamber upon an increase in car load and for increasing the volume of said chamber upon a decrease in car load, and mechanism for operatingsaid means.

17. In a brake apparatus, in combination, a valve device having a chamber and operative according to the increase and decrease in pressure in said chamber to effect varying degrees of application and release of brakes, valve means automatically operative for supplying fluid under pressure to and releasing fluid under `pressure from said chamber for predetermined intervals of time for controlling the operation of said valvedevice, means for decreasing the volume of said chamber upon an increase in car load and for increasing the volume of said chamber upon a decrease in car load, and mechanism automatically operative upon a change in car load for operating said means.

18. In a brake apparatus, the combination With a brake cylinder, of fluid pressure operative means for supplying fluid under pressure to and releasing uid under pressure from said brake cylinder, a manually operated member movable in a brake controlling zone, valve means responsive to the movement of said member for supplying fluid under pressure to and releasing fluid under pressure from said iluid pressure operated means, means for varying the amount of fluid under pressure acting on said fluid pressure operated means by the operation of said valve means in accordance With the position of said member in said zone, and means for varying the pressure obtained on said fluid pressure operated means by said valve means according to the load on the car.

SAMUEL L. WILLIAMS. 

